Category Archives: SMT


Feb15
NWO (Non-Wet-Open) Defect in BGA Soldering: Causes and Possible Solutions

Recently, many have inquired about how to deal with Non-Wet-Open (NWO) issues when encountering BGA packaged ICs soldering. The defects associated with NWO are quite similar to those of HIP (Head-in-Pillow) and typically occur at the edges and corners of … Continue reading

Feb06
Purpose of Using Lead-Free Low-Temperature Solder (LTS) SnBi, SnBiAg in Soldering

The alloy composition of lead-free LTS (Low Temperature Solder) usually includes the metal “bismuth (Bi)” in addition to tin (Sn) to lower its eutectic point. The commonly used lead-free solder SAC305 has a melting point of 217°C, while Sn64Bi35Ag1 has … Continue reading

Jan16
RSS or RTS? Which SMT Profile Should You Choose?

Choosing between RSS (Ramp-Soak-Spike) and RTS (Ramp-To-Spike) for the reflow temperature profile in the SMT (Surface Mount Technology) process has been a constant dilemma for many engineers. Some face pressure from higher-ups to opt for RTS due to cost-saving benefits, … Continue reading

Jan09
HIP (Head-in-Pillow) Defect Phenomenon: Possible Causes in SMT Reflow Process

The HIP (Head-in-Pillow) defect looks like a person resting their head on a pillow, not buried inside it. Recently, some people refer to it as HoP (Head-on-Pillow). Both terms refer to the non-wetting defect in the solder joints of BGA … Continue reading

Jan02
SMT Reflow Soldering Temperature Profiles Explanation and Precautions

The thriving development of the electronics industry owes much to the invention and improvement of Surface Mount Technology (SMT). Among the various SMT techniques, Reflow Soldering plays a pivotal role. In this discussion, we aim to shed light on some … Continue reading